minutes, 5 March 2015 SVG WG telcon

Minutes from this week’s telcon are here:

  http://www.w3.org/2015/03/05-svg-minutes.html

and below as text.


   [1]W3C

      [1] http://www.w3.org/

                               - DRAFT -

                    SVG Working Group Teleconference

05 Mar 2015

   [2]Agenda

      [2] https://lists.w3.org/Archives/Public/www-svg/2015Mar/0009.html

   See also: [3]IRC log

      [3] http://www.w3.org/2015/03/05-svg-irc

Attendees

   Present
          Thomas_Smailus, krit, [IPcaller], ed, heycam, AmeliaBR,
          [Microsoft], stakagi, Tav, nikos

   Regrets
   Chair
          ed

   Scribe
          Cameron

Contents

     * [4]Topics
         1. [5]computed value for <length>
         2. [6]SVG 2 Chapter Assessment
         3. [7]Text Issue 3 - semantics of foreignObject
         4. [8]Issue 13, 15: Allow 'shape-inside', 'shape-outside'
            to reference an image
         5. [9]Issue 35: Does shape-padding effect text laid out
            using 'extent'
         6. [10]Issue 54, 55, 56, 57 - should shadownodes ever be
            returned in
            getIntersectionList/getEnclosureList/checkIntersection
            /checkEnclosure?
         7. [11]Issue 49 and 50 - issues belong in geometry or
            styling chapters (should be defined once for all
            presentation attributes)
         8. [12]Issue 48 - we need to reference HTML.next for
            this, can we do that? html5 REC doesn't have this
         9. [13]Issue 39 and 40 - types chapter removed the
            list-of-t definition, use HTML's set of
            space-separated tokens definition instead?
        10. [14]Issue 34 - wasn't entirely clear from f2f minutes,
            should scripts in external <use> documents run?
        11. [15]Issue 32 - drop the offending paragraph? Still add
            example?
        12. [16]Issue 23 - other namespaced markup in title and
            desc, what is the purpose?
        13. [17]Are xpointer target fragments still supported?
     * [18]Summary of Action Items
     __________________________________________________________

   <trackbot> Date: 05 March 2015

   <scribe> Scribe: Cameron

   <scribe> ScribeNick: heycam

computed value for <length>

   <ed>
   [19]https://lists.w3.org/Archives/Public/www-svg/2015Mar/0005.h
   tml

     [19] https://lists.w3.org/Archives/Public/www-svg/2015Mar/0005.html

   ed: I was reviewing the spec, and I found that we have some
   properties that use <length> grammar from CSS
   ... and in our spec we say what the computed value is
   ... for some of our properties we don't say "absolute <length>"
   for the computed value
   ... I propose we align with the rest of CSS and have <length>
   computed values be absolute

   AmeliaBR: so the effect would be if you do getCS you would get
   the px value equivalent, rather than a percentage etc.?

   ed: yes
   ... well percentage is special, but other units yes you would
   get px back

   AmeliaBR: as you say, it's what CSS does

   krit: percentage would still be a percentage in the computed
   value

   ed: if no one objects to that, I'd be happy to udpate the spec

   (no objection)

   RESOLUTION: Properties defined in SVG will have <length> values
   compute down to absolute px values.

   <scribe> ACTION: Erik to update SVG 2 to make properties with
   <length>s compute down to absolute px values. [recorded in
   [20]http://www.w3.org/2015/03/05-svg-minutes.html#action01]

   <trackbot> Created ACTION-3763 - Update svg 2 to make
   properties with <length>s compute down to absolute px values.
   [on Erik Dahlström - due 2015-03-12].

   ed: we sometimes define the parsing as <length> | <percentage>
   | <number>
   ... but most numbers use <length> | <percentage>

   AmeliaBR: I think there's text that says "a bare number is a
   length with an implicit unit"

   <AmeliaBR>
   [21]https://svgwg.org/svg2-draft/types.html#InterfaceSVGLength

     [21] https://svgwg.org/svg2-draft/types.html#InterfaceSVGLength

   <AmeliaBR> correction:
   [22]https://svgwg.org/svg2-draft/types.html#syntax

     [22] https://svgwg.org/svg2-draft/types.html#syntax

   <AmeliaBR> Quote: "The insertion of the <number> symbols allows
   for unitless length and angles to be used in presentation
   attribute while disallowing them in corresponding property
   values."

   heycam: what I tried to do was make presentation attributes
   accept numbers implicitly (because properties defined in CSS
   specs don't include number explicitly)
   ... for properties defined in SVG, though, they include number
   explicitly

   krit: I don't think we need wording here for presentation
   attributes
   ... because CSS defines that presentation attributes allow
   unit-less numbers

   heycam: can you please give me a link to that text

   <scribe> ACTION: Cameron Talk to Tab about implicit number
   units in properties [recorded in
   [23]http://www.w3.org/2015/03/05-svg-minutes.html#action02]

   <trackbot> Created ACTION-3764 - Talk to tab about implicit
   number units in properties [on Cameron McCormack - due
   2015-03-12].

   AmeliaBR: I wanted to clarify the wording you've got there:
   "unitless numbers can only be allowed in presentation
   attributes"
   ... whereas currently we allow unitless numbers in SVG-specific
   style properties
   ... like stroke-width
   ... even if you're declaring that in a style sheet
   ... would we be disallowing that?

   krit: for these properties, they need to specify <number> as
   well
   ... stroke-dasharray, stroke-width, etc.

   heycam: I did intend to put <number> explicitly in stroke-width
   etc.

   krit: I don't think we want to have numbers on the geometry
   properties
   ... every new property should follow the general CSS way of
   defining properties
   ... stroke-width, stroke-dasharray, stroke-dashoffset and
   baseline-shift are the ones WebKit supports
   ... so for cx, cy, etc. we don't have the quirks mode enabled
   and so numbers aren't accepted

   ed: for the geometry ones I haven't allowed numbers in blink
   either

   AmeliaBR: do we want to add a note to encourage authors to
   always put explicit units?

   heycam: yes I think that'd be good

   krit: I think Tab suggested using quirks mode for these
   properties to get the numbers
   ... but adding <number> explicitly is fine as well
   ... I agree about adding a note

   <scribe> ACTION: Add a note about avoiding unitless values
   [recorded in
   [24]http://www.w3.org/2015/03/05-svg-minutes.html#action03]

   <trackbot> Error finding 'Add'. You can review and register
   nicknames at
   <[25]http://www.w3.org/Graphics/SVG/WG/track/users>.

     [25] http://www.w3.org/Graphics/SVG/WG/track/users

   <scribe> ACTION: Cameron Add a note about avoiding unitless
   values [recorded in
   [26]http://www.w3.org/2015/03/05-svg-minutes.html#action04]

   <trackbot> Created ACTION-3765 - Add a note about avoiding
   unitless values [on Cameron McCormack - due 2015-03-12].

   AmeliaBR: so all existing presentation attributes accept number
   as an alternative to length

   heycam: hypothetical question: if we introduced a new SVG
   property that wasn't previously an attribute, would we accept a
   number in the presentation attribute?

   krit: I'd say yes

   AmeliaBR: yes, good for consistency

   ed: the remaining question in my email was regarding how units
   are supposed to be handled when you serialize or interpolate
   values while animating
   ... and I found that implementations differ
   ... was wondering if this was defined in CSS
   ... so getCS and CSS Animations
   ... what happens if you animate from 2em to 10ex for example?
   ... what happens to the values in between?

   krit: I think there is no definition in CSS yet for this

   ed: was just wondering if it's defined somewhere

   heycam: shouldn't this be defined in Transitions/Animations?

   <AmeliaBR>
   [27]http://dev.w3.org/csswg/css-transitions/#animatable-types

     [27] http://dev.w3.org/csswg/css-transitions/#animatable-types

   krit: maybe should be, but isn't

   "when both values are lengths, interpolated as lengths" ...

   AmeliaBR: to go between 10px and 100%, you go beteween
   calc(10px + 0%) and calc(0px + 100%)

   heycam: oh, I forgot transitions/animations work between
   computed values
   ... so you'll have two px values

SVG 2 Chapter Assessment

   [28]https://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Chapter_Assess
   ment

     [28] https://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Chapter_Assessment

   heycam: I only got 2 of my 3 chapters done

   ed: since we started at the top last time, let's start at the
   bottom this time
   ... next available person, Text?

Text Issue 3 - semantics of foreignObject

   Tav: there was an issue in the spec asking to define the
   semantics of foreignObject
   ... I'm not sure we even have to talk about foreignObject here
   at all

   just before
   [29]https://svgwg.org/svg2-draft/text.html#TextLayoutContentAre
   a

     [29] https://svgwg.org/svg2-draft/text.html#TextLayoutContentArea

   "If more complex layout is required (bulleted lists, tables,
   etc.), text can be rendered in another XML namespace such as
   XHTML [XHTML] embedded inline within a ‘foreignObject’ element.
   (Note: the exact semantics of this approach are not completely
   defined at this time.) "

   heycam: how about just turn that paragraph into a note and
   point to the foreignObject chapter for more complex text layout
   support

   Tav: ok, sounds good

Issue 13, 15: Allow 'shape-inside', 'shape-outside' to reference an
image

   Tav: in the Shapes spec, these can link to images

   <ed> [30]https://svgwg.org/svg2-draft/text.html#TextShapeInside

     [30] https://svgwg.org/svg2-draft/text.html#TextShapeInside

   Tav: so you reference an image and a threshold, it's defining a
   shape using an image

   heycam: what is the issue? is that allowed?

   AmeliaBR: it is supported in a number of browsers in HTML

   Tav: so we should just allow it

   heycam: in terms of restrictions on external images, etc., that
   should be in Integration

   Tav: ok

Issue 35: Does shape-padding effect text laid out using 'extent'

   Tav: so where define an are to put text in (using 'extent') do
   we allow shape-padding to affect that?
   ... my feeling is no

   AmeliaBR: if you want to lay out text in a padding rectangle,
   you can create a rectangular shape and use shape-padding on it

   heycam: ok, that makes sense then

Issue 54, 55, 56, 57 - should shadownodes ever be returned in
getIntersectionList/getEnclosureList/checkIntersection/checkEnclosure
?

   ed: so say you have a rectangle, and you want all elements that
   are within the rectangle
   ... if you had a <use> in there, would you expect the elements
   referenced by the <use> to be returned, or just the <use>
   itself?
   ... I think my initial feeling is that it should just return
   the <use> element

   AmeliaBR: I would say so too
   ... that avoids some issues; if you're talking about individual
   nodes, or part of the <use> is fully enclosed but not the
   entire thing
   ... maybe long term we could have an extra parameter
   ... but by default, we should just return entire elements in
   the main DOM

   heycam: I think that makes sense

   ed: I haven't done any testing, though I would be surprised if
   an implementation returned shadow nodes

   AmeliaBR: last I checked, these methods aren't implemented in
   firefox

   RESOLUTION: getIntersectionList and friends can return a <use>
   but not the elements it references

   <scribe> ACTION: Erik to make getIntersectionList and friend
   return a <use> but not the elements it references [recorded in
   [31]http://www.w3.org/2015/03/05-svg-minutes.html#action05]

   <trackbot> Created ACTION-3766 - Make getintersectionlist and
   friend return a <use> but not the elements it references [on
   Erik Dahlström - due 2015-03-12].

Issue 49 and 50 - issues belong in geometry or styling chapters
(should be defined once for all presentation attributes)

   ed: what does SVGAnimatedLength return for the attributes we
   made properties
   ... I think this is a general issue
   ... should probably address this in the styling

   heycam: I have an issue to do that in the Types chapter

   ed: so I can remove mine?

   heycam: yes that's fine

Issue 48 - we need to reference HTML.next for this, can we do that?
html5 REC doesn't have this

   ed: there was some definition for the title and activeElement
   on SVGSVGElement
   ... which are defined in HTML.next but not HTML5 (W3C versions)

   heycam: I guess we have to then

   ed: ok
   ... there is a W3C WD version has these; I'll check

Issue 39 and 40 - types chapter removed the list-of-t definition, use
HTML's set of space-separated tokens definition instead?

   ed: i want to use this HTML definition
   ... e.g. for requiredFeatures
   ... it's a simple string-like attributes

   heycam: I was going to use that algorithm to use this algorithm
   for the class attribute
   ... so I was going to add another case in the attribute parsing
   section

Issue 34 - wasn't entirely clear from f2f minutes, should scripts in
external <use> documents run?

   ed: wasn't clear from the minutes that scripts run in external
   documents
   ... if the <script> is outside the subtree you're referencing

   AmeliaBR: if it's outside, I wouldn't expect it to run

   heycam: I can't recall the discussions we had on this, but I
   think not running the script is good

   AmeliaBR: right now we have an option to use a whole external
   file; we should be clear what happens with script

   heycam: so what about not running script in the resource
   document, and also not in the cloned shadow tree?

   ed: I think this could use some testing too
   ... so I will probably do taht
   ... but trying to restrict scripting would be good

   AmeliaBR: was a decision made about <use> referencing a
   <foreignObject>?
   ... some browsers copy the <foreignObject> content, some don't

   ed: I don't think we've discussed that issue

   AmeliaBR: you're only supposed to reference graphics content,
   but you can have a <foreignObject> in a <g>
   ... so what happens if you have other, non-graphical content
   within a <g>

   BogdanBrinza: for IE, it gets cloned and rendered like a
   regular <use> element
   ... there's no special behaviour for foreignObject
   ... (though we don't have public builds for that yet)

   AmeliaBR: do you know whether the copy is an interactive copy?
   or just an image of the original object?
   ... e.g. if it has form controls?

   BogdanBrinza: I am not sure... but I can try it, good question
   ... if it's cloned it should be interactive

   ed: would appreciate some help with testing this

   BogdanBrinza: I can help with Windows/OSX testing

   ed: mostly asking for help with writing tests

   BogdanBrinza: I can help with that too
   ... we do have some tests you can reuse

   <scribe> ACTION: Bogdan to help Erik test unusual elements
   inside <use>d subtrees [recorded in
   [32]http://www.w3.org/2015/03/05-svg-minutes.html#action06]

   <trackbot> Created ACTION-3767 - Help erik test unusual
   elements inside <use>d subtrees [on Bogdan Brinza - due
   2015-03-12].

Issue 32 - drop the offending paragraph? Still add example?

   ed: this is about the <use> element
   ... there's a paragraph that talks about visibility

   <ed> [33]https://svgwg.org/svg2-draft/struct.html#UseElement

     [33] https://svgwg.org/svg2-draft/struct.html#UseElement

   ed: and how visibility:hidden does something particular
   ... not sure it's necessary to have this paragraph
   ... the issue asks why visibility is called out specially
   ... and that it might be better to have an example to show what
   it's trying to describe
   ... not sure what the example would be like, thouhg
   ... I'd be happy just dropping that para

   AmeliaBR: I think it's an interesting example, but definitely
   should be an informative note or example, not part of the
   normative text

   ed: just not sure there's a good example not shown by the other
   examples

   <scribe> ACTION: Amelia to think of an example of struct.html
   issue 32 [recorded in
   [34]http://www.w3.org/2015/03/05-svg-minutes.html#action07]

   <trackbot> Created ACTION-3768 - Think of an example of
   struct.html issue 32 [on Amelia Bellamy-Royds - due
   2015-03-12].

Issue 23 - other namespaced markup in title and desc, what is the
purpose?

   ed: I think the issue is to say what this purpose is

   heycam: presumably to include some more structured descriptions
   rather than just plain text

   AmeliaBR: and originally also so that you could have complex
   fallback content, in a browser that didn't support SVG
   ... that's no longer relevant though
   ... I'm pretty sure the main purpose is so you can have
   structured content inside <desc>

   heycam: note also the HTML parsing algorithm allows HTML
   content inside here

   AmeliaBR: I'm not sure if there's much of a benefit within
   <title>, but some browsers do support <br> within <title> and
   some don't
   ... a weird random thing
   ... maybe that should be cleaned up

   heycam: within SVG documents or HTML title?

   <AmeliaBR>
   [35]http://stackoverflow.com/questions/23626422/tooltip-to-disp
   lay-in-two-separate-lines-not-working-in-firefox/25690802#25690
   802

     [35] http://stackoverflow.com/questions/23626422/tooltip-to-display-in-two-separate-lines-not-working-in-firefox/25690802#25690802

   AmeliaBR: so this may have been coming from this comment that
   external namespaces are OK
   ... so some support <br> within title

   Tav: I don't really like the idea of having <br> in there
   ... maybe white-space:pre-line?

   AmeliaBR: that's the other thing that's changed since SVG 1.1
   ... in the title="" in HTML you can put line breaks
   ... so either way isn't conforming to specs, but all browsers
   allow one way or the other
   ... either with <br> or a hard line break

   heycam: and that's a hard line break without setting the
   white-space property?

   AmeliaBR: yes
   ... and only for <title>

   Tav: putting a <br> seems wrong to me
   ... allowing white space to be preserved seems more compatible

   AmeliaBR: and with the new white-space option, I think that
   will be more reasonable

   Tav: you can style your title

   AmeliaBR: it's tricky, because tooltips aren't styled with CSS
   ... I have no idea whether white-space:pre would apply

   heycam: do you think we need a issue in here to define this
   kind of thing?

   <scribe> ACTION: Erik to add purpose for markup within
   title/desc [recorded in
   [36]http://www.w3.org/2015/03/05-svg-minutes.html#action08]

   <trackbot> Created ACTION-3769 - Add purpose for markup within
   title/desc [on Erik Dahlström - due 2015-03-12].

   <scribe> ACTION: Erik to add an issue to describe the behaviour
   of markup within title/desc (regarding line breaking, at least)
   [recorded in
   [37]http://www.w3.org/2015/03/05-svg-minutes.html#action09]

   <trackbot> Created ACTION-3770 - Add an issue to describe the
   behaviour of markup within title/desc (regarding line breaking,
   at least) [on Erik Dahlström - due 2015-03-12].

Are xpointer target fragments still supported?

   AmeliaBR: ChrisL says XPointer stuff should all have been
   removed from the spec
   ... so I think we can just remove this

   ed: yes I think that's right

   <scribe> ACTION: Amelia to clean up the reference to XPointer
   in the spec [recorded in
   [38]http://www.w3.org/2015/03/05-svg-minutes.html#action10]

   <trackbot> Created ACTION-3771 - Clean up the reference to
   xpointer in the spec [on Amelia Bellamy-Royds - due
   2015-03-12].

   trackbot, end telcon

Summary of Action Items

   [NEW] ACTION: Add a note about avoiding unitless values
   [recorded in
   [39]http://www.w3.org/2015/03/05-svg-minutes.html#action03]
   [NEW] ACTION: Amelia to clean up the reference to XPointer in
   the spec [recorded in
   [40]http://www.w3.org/2015/03/05-svg-minutes.html#action10]
   [NEW] ACTION: Amelia to think of an example of struct.html
   issue 32 [recorded in
   [41]http://www.w3.org/2015/03/05-svg-minutes.html#action07]
   [NEW] ACTION: Bogdan to help Erik test unusual elements inside
   <use>d subtrees [recorded in
   [42]http://www.w3.org/2015/03/05-svg-minutes.html#action06]
   [NEW] ACTION: Cameron Add a note about avoiding unitless values
   [recorded in
   [43]http://www.w3.org/2015/03/05-svg-minutes.html#action04]
   [NEW] ACTION: Cameron Talk to Tab about implicit number units
   in properties [recorded in
   [44]http://www.w3.org/2015/03/05-svg-minutes.html#action02]
   [NEW] ACTION: Erik to add an issue to describe the behaviour of
   markup within title/desc (regarding line breaking, at least)
   [recorded in
   [45]http://www.w3.org/2015/03/05-svg-minutes.html#action09]
   [NEW] ACTION: Erik to add purpose for markup within title/desc
   [recorded in
   [46]http://www.w3.org/2015/03/05-svg-minutes.html#action08]
   [NEW] ACTION: Erik to make getIntersectionList and friend
   return a <use> but not the elements it references [recorded in
   [47]http://www.w3.org/2015/03/05-svg-minutes.html#action05]
   [NEW] ACTION: Erik to update SVG 2 to make properties with
   <length>s compute down to absolute px values. [recorded in
   [48]http://www.w3.org/2015/03/05-svg-minutes.html#action01]

   [End of minutes]
     __________________________________________________________

-- 
Cameron McCormack ≝ http://mcc.id.au/

Received on Thursday, 5 March 2015 21:34:50 UTC